Starter gearing



Sept 24 w M.Y P. WHITNEY' MSNM v i. STARTER GEARING Filed June 14, 19353 Shees-Sheet l wmp/65:

V` i I .4 1 7mm/E) Sept1 24, H935. M. 1:l WHITNEY STARTER GEARING YFiled June 14, 1933 A 3 Sheets-Shf.=,e'rl 2 f NVENTOR Y M 2f.

ATTORNEY Sep" 24 M. P. WHITNEY STARTER GEARING Filed June 14, 1933 3Sheets-Sheet 5 /N VEA/TOR l mms- M f l ATTORNEY Patented Sept. 24, 1935PATENT OFFICE STARTER GEARING Maurice P. Whitney, Elmira, N. Y.,assigner to4 Eclipse Machine Company, Elmira Heights, N. Y., acorporation of New York Application June 14, 1933, Serial No. 675,741

15 Claims.

This invention relates to starter gearing and more particularly to adrive for automatically connecting and disconnecting a starting motorwith a member of an engine to be started.

It is an object of the present invention to provide -an engine starterdrive which is small and compact but of rugged construction and highlyeicient in operation.

It is another object to provide such a device embodying provisions forsecuring continuous cranking until the engine starts.

A further object is to provide' such a device which incorporatesstructure for preventing the transmission of any substantial drivingeiect from the engine to the armature of the starting motor.

It is a further object to provide such a device' in which means areincorporated for ensuring proper engagement between the engine drivingmember and the member of the engine to be driven.

It is an other object to provide such a device having ample torquecapacity but which is not liable to stick or jam.

It is another object tol provide such a device in which the kineticenergy of the engine driving member and associated parts at the time ofdisengagement from the engine member is dissipated in friction ofslipping clutch surfaces in a manner to preventrebounding of the partstoward operative position.

A further object is to provide such a device' which is entirelyself-contained as a simple unit which may be readily slipped on a motorshaft and xed thereto. v

Further objects and advantages will be apparent from the'followingdescription taken in4 connection with the accompanying drawings inwhich:

Fig. 1 is a side elevation partly in section of a preferred embodimentof the invention show ing the parts in their normal idle position.

Fig. 2 'is a similar view showing the parts in driving position.

Fig. 3 is asimilar view showing the parts in the positions assumed whenthe engine drivingv member abuts against the member of the engine to bestarted instead of properly meshing therewith.

Fig. 4 is a perspective view of the engine driving member and the partsassociated therewith, the various elements being shown in extendedYdisassembled relation.

Fig. 5 is a similar view of the screw shaft and its associated parts.

Fig. 6 is a view similar to Fig. 1 ofa second embodiment of theinvention. I

Fig. 7 is a similar view showing the parts in driving position; and

Fig. 8 is a perspective view of a preferred form 5 of a barrel memberfor connecting the driving clutches with the engine driving member asi1- lustrated in Figs. 6 and '7.

Referring first to Fig. 1 of the drawings, there is illustrated a powershaft I which may be the 10 extended armature'shaft' of a startingmotor,

not illustrated. An engine driving member in the form of a pinion 2 isfreely journalled on the power shaft I inv position to be movedlongitudinally into and out of engagement with a mem- 15 ber 3 such as aflywheel gear of the engine to be started.

Means are provided for moving the pinion 2 into and out of engagementwith the engine gear 3 and for rotating the pinion to drive the engine20 gear comprising a, hollow shaft i adapted to be suitably fixed to thepower shaft I vas by means of a key 5 and set screw 6 and having stopmembers 8 and 9 suitably fixed to its respective ends, a barrel memberI3 fixed to the pinion 2, and a 25 friction clutch including a drivingcone element II having an inclined plane connection with the shaft'and adriven cone element I2 splined to the barrel. As here illustrated, theinclined plane connection yis provided by reducingv and thread- 30 ing aportion of the shaft as indicated at l, and threading the drivingelement thereon, and vthe splined connection vis formed by means ofradially extending teeth Id on the driven clutch element i2 slidablyengaged in longitudinal slots v35 I5 in the barrel i3. The slots i5terminate at shoulders i6 forming a positive limit for the telescopingmovement of the clutch element i2.

The driving clutch element I i is retained within the barrel I3 bysuitable means such as a re- 40 taining disk I 'i having radiallyextending portions I8 engaging in the slots I5, and a lsplit ring I Sarranged to be sprung within a fiange 2i formed on the end of the barrelI3. It will Ahe noted that the clutch elements are so dimenthrustring 26which bears against the radially extending teeth I4 of the outer clutchelement I2. Since the inner clutch element II is retained in the barrelby the disk I1 andthe clutch element I2 is spaced from said disk asabovedescribed, it will be readily appreciated that the pressure ofspring 23 maintains the clutch elements in frictional engagement at alltimes.

Load responsive means for compressing the clutch elements II, I2 for thetransmission of cranking torque is provided in the form of acomparatively heavy compression clutch spring 21 within the barrel I3normally engaging the outer clutch element I2 at one end and bearing atits other end against a thimble 28 which is slidably mounted on thesmooth portion of the hollow shaft 4 and has-a loose sliding iit withinthe barrel I3. The thimble 28 normally bears against a shoulder 29 inthe interior of said barrel being maintained in engagement therewith bya comparatively light compression spring 3| located between said thimbleand the stop member 8.

In order to attach the pinion 2 to the barrel,

.the pinion is provided with a flange member 32 suitably fixed thereonas by means of inwardly extending teeth 33 formed to engage a turneddown portion of the teeth of pinion 2 and clamped between a shoulder 34at the end of such turned down portion and a ring 35 which is rivetedagainst the flange by peening over the end of the pinion 2 as shown at36. The rim of the ilange 32 is provided with axially extending fingers31 arranged to engage in slots 38 in the end of the barrel I3, andsuitably retained therein as by means of a split ring 39 which is sprungunder a retaining flange 4I (Fig. 2) of the barrel.

It will thus be seen that the pinion 2 is rigidly A connected to one endof the barrel I3, while the clutch I I, I2 is splined to the other end,the pinion and barrel assembly being retained in its idle position'bythe anti-drift spring 3l. The idle position of the drive is dened by thestop 8 which is illustrated as a sleeve threaded on the outer end of thehollow shaft 4 and retained thereon by the set screw 6.

Means are provided for maintaining continuous cranking until the enginestarts, in the form of a centrifugal device which holds the pinion 2 inmesh with the engine gear 3 until rendered inoperative by rotation ofthe pinion and barrel assembly above a predetermined speed. As hereshown this device comprises a plurality of latch members 43 slidablymounted in openings 44 in the barrel and normally projecting thereinsuiilciently to engage a radial flange 45 on the stop member 8 when thepinion 2 is in operative position as illustrated in Fig. 2. The flange45 and the latch members 43 are bevelled on one side as indicated at 46and 41 respectively so that the latch members pass over the flangefreely during the meshing movement of the pinion 2. Thereafter thelatches are urged inwardly by suitable the barrel as shown at 49 wherebythe latches maintain the pinion in driving position during cranking.When the barrel I3 rotates at sufficient speed, however, the centrifugalforce of the latch members 43 overcomes lthe pressure of the springs 48causing the latches to be retracted out of engagement with the flange45. The pinion assembly is thereupon free to move to idle position underthe influence of the spring 3l. 'I'he outwardv motion of the latchmembers 43 under the influence of centrifugal force is limited bySuitable means such as the shouldered screws II xed to the barrel I3.

In the operation of this embodiment of the invention, rotation of thepower shaft I from the starting motor causes the rotation of the hollow5 shaft 4, and since the clutch element II is prevented from rotatingtherewith by reason of its frictional engagement with the clutch elementI2 and the inertia of the clutch and pinion assembly, the clutch elementII is caused to traverse the 10 screw threads I whereby the barrel andpinion assembly is moved longitudinally to mesh the pinion with theengine gear as shown in Fig. 2. After meshing is completed, furtherlongitudinal motion of the barrel and pinion assembly is pre- 15 ventedby the engagement of the thimble 28 with the stop member 8 on the screwshaft whereupon the further rotation of the power shaft causes theclutch II, I2 to move longitudinally in the barrel I3 compressing thespring 21 against the 20 thimble 28 until sufficient torque has beenbuilt up through the screw jack action of the triple threads workingagainst the compression of spring 21 to equcl the torque resistance ofthe flywheel and thereby cause rotation of the pinion to crank 25 theengine.

During the cranking operation, it will be'understood that variations inthe load on the pinion 2 caused by the engine passing over itscompression points may cause the clutch elements II, I2 to 30 hunt backand forth along the threads 1 to some extent, but the pinion is held infull mesh with the engine gear by virtue of the splined connection ofthe clutch I I, I2'on the barrel I3 which permits the clutch to moveback and forth in the barrel. 35 as well as by the latch members 43which are maintained in position to engage the flange 4l at all crankingspeeds and positively hold the pinion in cranking position. y

When the engine starts, the acceleration of the 40 engine gear causesthe pinion to overrun the power shaft whereby 'the clutch II, I2 ismoved back to idle position, relaxing the pressure of the spring 21thereon. The driving effect of the engine gear on the pinion 2thereafter causes the 45 clutch II, I2 to overrun which permits thebarrel to be accelerated to suillcient speed to move the centrifugallatches 43 to inoperative position. The spring 3I thereupon becomeseffective to move the pinion and barrel assembly to idle position.l50

It will be noted that during the time that the flywheel is driving thepinion, the armature of the starting motor is substantially disconnectedfrom the pinion, so that no appreciable driving eifect is transmitted tothe armature.

In case during the engaging operation, a tooth of the pinion comes intoabutting relation with a tooth of the engine gear so that thelongitudinal motion of the barrel is stopped, continued longitudinalmovement of the clutch II, I2 comco presses the spring 23 as shown inFig. 3, thereby storing up energy in said spring for snapping the lresilient means such as the springs 48 attached to pinion into mesh withthe nywhl when the teeth are properly indexed, and correspondinglycomsembly is projected forward Lby the expansion of terval to allow theindexing to take place, and

the spring serves to snap the pinion into initial meshi'ngrelation assoon as the indexing takes place, whereby milling of the pinion teethagainst the teeth of the engine gear is prevented.

The spline slots I5 in the barrel are preferably formed of such lengththat the thimble 2,8 engages the stop in case of tooth abutment beforethev clutch element I2`engages the shoulders IB so that the main clutchspring 21 is compressed somewhat, and the clutch correspondinglytightened prior to the positive closure of the clutch due to theengagement of the clutch element I2 with said shoulders.

It will be readily appreciated that the pinion and barrel assembly, withthe clutch element l2 has considerable rotational inertia so that thedemeshing action thereof is brought about not only by the spring 3i butalso by the drawing action of the clutch element II which isfrictionally connected to the barrel by virtue of the pressure of spring23, and is therefore caused to overrun the screw shaft .4. When theclutch element II strikes the stop 9, further backward motion of theentire assembly is prevented, but any tendency to rebound toward theengine gear is suppressed by reason of the fact that the continuedrotation of the pinion and barrel causesl the clutch element I I to befirmly held against the stop 9 whereby the disk I'l effectively holdsthe barrel and associated parts in idle position.

In Figs. 6, 7, and 8 there is illustrated another embodiment of theinvention providing for additional torque capacity of the drive withoutincreasing the size or weight of the parts thereof As here shown theelements of the pinion and barrel assembly, the clutch and screw shaftare the same as in the embodiment first described and are similarlynumbered, but the thimble 28@ and the stop 8@ which form the abutmentfor lthe main vclutch spring 21 are formed in the shape of cooperatingclutch elements, and the thimble 230 is provided with radially extendingkey elements i slidably mounted in slots 282 in the barrel I3. Thespring 3i normally maintains the key elements 28| of the thimble 280against the shoulders 290 formed by the ends of the slots 262, thusperforming its anti-drift function as in the first embodiment. However,since the clutch thimble 220 is splined as above described to the barrelI3, the barrel is connected to the hollow shaft t by the clutch formedby the elements Bil and 280 as well as by the clutch il, I2, when themeshing motion of the pinion and barrel assembly compresses the spring21 between the driven elements 28@ and I2 of said clutches.

The barrel may beformed as indicated in Fig. 8 from a sheet metal blankwhich'is stamped out and then rolled and locked together by suitablevmeans such as the dove-tail joint I 30 as shown.

In this case the locating ange for'the ring 24 corresponding to theflange 25 in the rst embodiment of the invention is preferably formed asa series of struck up portions 250 which serve to locate the ring 24 andhence form an abutment for the spring 23.

The operation of this embodiment of the invention is the same as thatpreviously described except for the additional clutching effect be.-tween barrel and hollow shaft caused by the additional clutch elements80 and 280. This per- 5 mits the use of somewhat steeper angles for theclutching surfaces whereby any possible danger of wedging and jamming ofthe clutches is prevented.

What is claimed is: 10 l. In an engine starter, a power shaft, a hollowscrew shaft fixed thereto, a friction clutch having a threadedconnection with the screw shaft, a member. movably mounted on the powershaftto engage and drive a member of the engine l5 to be started,connections including a barrel member for actuating the engine driving4mem-- ber from the clutch, a stop member on saidscrew shaft, and acompression spring on the screw shaft between the clutch and stop memberar- 20 ranged to be compressed therebetween by further movement of theclutch on the screw shaft after the engine driving member has been movedto operative position.

2. In a starter drive, a shaft, a friction clutch 25 comprising adriving element, means connecting Saiddriving clutch element to saidshaft for concmitant rotary and longitudinal movement thereon androtation therewith, a pinion freely mounted cn the shaft to engage anddrive an 30 engine gear, a barrel member fixed to the pinion, saidclutch having a driven element splined to the barrel, a positive stopfor the barrel in its operative position and yielding means engagingsaid stop for limiting the movement of the driven 35 clutch element inthe engaging direction whereby further movement of the clutch after thebarrel engages said stop causes tightening thereof to transmit crankingtorque.

.3. In a starter drive, a shaft, a friction clutch w comprising adriving element, means connecting said driving clutch element to saidshaft for eon-V comitant rotary and longitudinal movement thereon androtation therewith, a, pinion freely mounted on the shaftito engage anddrive an engine gear, a barrel member xed to the pinion, said clutchhaving a driven element splined to y the barrel, an abutment xedrelative to said shaft Within said barrel, a thrust member slidablycarried by saidshaft within said barrel, said barrel having means forlimiting the sliding movement of the thrust member therein, meansinterposed between the abutment and thrust member for yieldably spacingthe same and holding the thrust member against said limiting means, andmeans for yieldingly holding the thrust member and the driven clutchmember in spaced relation.

4. In an engine starter, a power shaft, a hollow screw shaft fixedthereto, a member slidably journailed on the power shaft to engage anddrive a member of the engine to be started, a clutch comprising adriving element having a threaded connection with the screw shaft, and adriven element, means including a barrel member for connectingthe-driven clutch element to the engine driving member, said screw shafthaving an abutment, a light compression vspring and a heavy compressionspring on the screw shaft between the clutch and abutment, said lightspring serving to normally maintain the parts in idle position, and saidheavy spring serving to close the clutch for the transmission of drivingtorque after the parts have been moved to driving position.

' 5. In an engine starter drive, a power shaft, an engine driving membermounted for longitudinal movement thereon into. and out of engagementwith a member of the engine to be started, and for rotary movementtherewith to drive said engine member, means for actuating the enginedriving member from the power shaft including a clutch, means connectingsaid clutch to said shaft for rotary and longitudinal movement thereonand rotation therewith, and a barrel member non-rotatably connected tothe engine driving member and clutch, a thimble having limited slidingmovement within the barrel, a stop for the thimble mounted on the shaft,a spring between the thimble and stop normally holding the drive in idleposition, and a spring between the clutch and thimble arranged to becompressed when the thimble engages the stop to thereby tighten theclutch.

6. In a starter drive, a shaft, a friction clutch comprising a drivingelement, means connecting said driving element to said shaft for rotaryand longitudinal movement thereon and rotation therewith, a pinionfreely mounted on the shaft -to engage and drive an engine gear, abarrel member xed to the pinion, said clutch having a driven elementsplined to the barrel, and means normally holding said barrel and clutchin extended relation, said means being adapted to yield and allowtelescoping thereof in case of tooth abutment between the pinion andgear, and

means for thereafter tightening said clutch for transmission of indexingtorque.

'7. In a starter drive, a shaft, a friction clutch comprising a drivingelement, means connecting said driving element to said shaft fory rotaryand longitudinal movement thereon and rotation therewith, a pinionfreely mounted on the shaft to engage and drive an engine gear, a barrelmember xed to the pinion, said clutch having a driven element splined tothe barrel, and means normally holding said barrel and clutch inextended relation, said means being adapted lto yield and allowtelescoping thereof in case of tooth abutment between the pinion andgear, said barrel having 'a retaining member for the driving element ofsaid clutch whereby the holding means serves to maintain the elements ofthe clutch in frictional engagement.

8. In an enginestarter drive, a power shaft, ay,

pinion freely joumalled thereon for longitudinal movement into and outof engagement with a gear of an engine to be lstarted and for rotationtherewith to crank said engine, means for actuating the pinion from thepower shaft including a barrel member xed to the pinion, a frictionclutch splined to said barrel and means connecting said clutch to saidshaft for rotary and longitudinal movement thereon and rotationtherewith, yielding means for closing said clutch and for limiting thetravel of said clutch, and yielding, means for opposing the longitudinalmovement of the clutch with respect to said barrel.

9. In an engine starter drive, a power shaft, a

" pinion freely journalled thereon for longitudinal' movement into andout of engagement with a gear of an engine to be started and forrotation therewith to crank said engine, means for actuating the pinionfrom the power shaft including a barrel member fixed to the pinion, afriction clutchsplined to said barrelv and means connecting said clutchto-said shaft for rotary and longitudinal movement thereon and rotationtherewith, clutch controlling means for limiting the travel of saidclutch and serving to tighten the clutch for the transmission ofcranking torque, and yielding means for opposing the longitudinalmovement of the clutch with respect to the barrel, the parts being soarranged that in case longitudinal movement of the barrel is preventedby the tooth abutment between the pinion and gear. the yielding opposingmeans is initially compressed before the clutch reaches the limit of itsmovement. 1

-10. In an engine starter drive, a power shaft, a driving member mountedthereon, means for moving the driving member into and out of engagementwith a member of the engine to be started, means for rotating thedriving member from the power shaft including an overrunning connectioneffective independent of translational movement of the ydriving member,means for holding said driving member in engagement with the enginemember, and mounting means for said holding means normally maintainingsaid holding means in operative position but adapted to yield at apredetermined rotational speed of the drive and permit the holding meansto move to inoperative position responsive to centrifugal force. s

1l. In an engine starter drive, a power shaft, a drivingmember mountedfor movement thereon into and out of engagement with a member of theengine to be started, means for rotating the driving member from lthepower shaft including a friction clutch and load responsiver means fortightening said clutch, means for holding said driving member inengagement with the engine member, and mounting means normallymaintaining said holding means in operative position but adapted toyield at a predetermined rotational speed of the drive and permit theholding meansto move to inoperative position responsive to centrifugalforce.

l2. In a starter drive a powershaft, an engine driving member and adriving connection therebetween including a pair of friction clutches,yielding means normally closing one clutch and yielding load responsivemeans for tightening both clutches for the transmission of crankingtorque. f

13.A In a starter drive for internal combustion engines, a power shaft,a member movable thereon into 'and out of engagement. with a member ofthe engine to be started, and means for actuating the engine drivingmember from the shaft including a driving clutch element, meansconnecting said driving clutch element to said shaft for rotary andlongitudinal movement thereon and rotation therewith, a driven clutchelement non-rotatably connected to the engine driving member, a yieldingelement in the path of movement of the driven clutch member, a stopfixed relative to said shaft and an abutment cooperating therewith forlimiting'the longitudinal movement of the yielding element to therebyyieldln'gly limit the longitudinal movement of the clutch, said stop and`abutment comprising .additional clutch `members connected .respectively.to .the power shaft and engine driving member.

14. In a starter drive for internal combustion engines, a power shaft, amember movable there- .on and therewith to engage and drive a member ofthe engine to be started, and means for ,actuating the engine drivingmember from the power shaft including a pair of driving clutch elementsconnected to be rotated by the shaft, a pair of driven clutch elementshaving a splined connection with the engine driving member, mean;

for holding a driving anda driven clutch element in initial engagement,and yielding load responsive means for causing driving engagement of allthe driving and driven clutch elements.

15. In an engine starter drive, a power shaft, a driving member mountedfor movement thereon into and out of engagement with a member of theengine to be started, means for rotating the driving member from thepower shaft including an overrunningl connection effective 'independentoi' translational movement of the drive ing member, a centrifugal detentfor holding the driving member in operative position, and mounting meansfor said detent normally maintaining said holding means in operativeposition but adapted to yield at a predetermined rotational speed of thedrive and permit the holding means to move to inoperative positionresponsive to centrifugal. force.

MAURICE P. WHITNEY. l0

